Planning is underway on a major upgrade of Perth's oldest wastewater treatment plant, with an initial $105 million committed to detailed design and site preparation at the Subiaco Water Resource Recovery Facility in Shenton Park, according to a report published 22 October 2026 by The National Tribune. The Cook Labor Government says the project will support 60,000 future homes across the city's inner and western suburbs and create several hundred construction jobs.
Key takeaways
- The Subiaco facility in Shenton Park, operating since 1927, currently treats about 65 million litres of wastewater per day from 120,000 homes and businesses, according to The National Tribune.
- An initial $105 million will fund detailed project design, engineering work and site preparation for a compact, ultra-modern plant on the Lemnos Street site, The National Tribune reports.
- Planned capacity increase: around 23 million litres per day, enough to support new homes for more than 135,000 people over the next 25 years, per The National Tribune.
- More than half a billion dollars is being invested by the state government in water infrastructure to enable housing development, The National Tribune reports, sitting inside a wider $10.8 billion housing investment since 2021.
- Engineering studies will examine advanced odour control systems to improve local amenity, according to The National Tribune.
What happened: an upgrade for a 1927 plant
Water Corporation's Subiaco Water Resource Recovery Facility has been treating wastewater since 1927 and currently processes about 65 million litres per day from a catchment running from Scarborough to North Fremantle and east to Maylands, The National Tribune reports. The initial $105 million is intended to fund detailed project design, engineering work and site preparation for a compact, ultra-modern plant to be built on the Lemnos Street site.
Under the plan, treatment capacity would increase by around 23 million litres per day, with Water Minister Daniel Pastorelli saying the spending is "the next step in creating more opportunities to recycle water and reduce demand on our drinking water supplies while supporting 60,000 future homes," as quoted by The National Tribune. Housing and Works Minister John Carey said the upgrade would support 60,000 future homes across Perth's infill and redevelopment areas, including Subi East, Belmont Park Racecourse and Fremantle Port, according to The National Tribune.
Reported numbers at a glance
| Item | Reported figure |
|---|---|
| Initial funding for design and site prep | $105 million |
| Current treatment capacity | ~65 million litres per day |
| Planned capacity increase | ~23 million litres per day |
| Future homes supported | 60,000 |
| Population served by upgrade (25-year horizon) | more than 135,000 people |
| State housing investment since 2021 | $10.8 billion |
All figures above are drawn from The National Tribune. The outlet also reports that the project is part of a broader state programme of more than half a billion dollars for water, wastewater and drainage infrastructure to unlock housing in Western Australia.
What it means for plant managers, engineers and procurement
The reported capacity figures convert directly into buyer units: the planned 23 million litres per day uplift is 23,000 m³/day, taking the facility from the stated 65,000 m³/day to roughly 88,000 m³/day once the new plant is commissioned. The 135,000-person population figure over a 25-year horizon implies, by simple ratio against the existing 120,000-home load, a long-run design horizon tied to growth in infill suburbs rather than a step-change in industrial load.
For a greenfield train of this size, the conventional specification is screening and grit removal, primary clarification, biological treatment (an A2O or MBR configuration is the most common for Australian resource-recovery plants targeting water reuse), and tertiary treatment with disinfection for recycled-water end use. The reported scope is a compact, ultra-modern plant on the Lemnos Street site, with the 23,000 m³/day increase sitting in the biological-to-tertiary envelope and an explicit engineering study into advanced odour control, which is consistent with the MBR-class envelope covered on the Mbr Membrane Systems hub and the broader Industries We Serve overview. For a municipal authority running a large conventional activated-sludge plant looking at capacity expansion, higher treated-effluent quality, and water-reuse supply, this procurement signals a design-and-build package with MBR-class biological and tertiary stages, an explicit odour-control scope, and a multi-year build horizon. Reference designs for similar municipal retrofits and BWRO polishing trains for reuse are outlined in the BWRO Plant 2026: Design, Cost & Operating Guide and the Municipal product hub. Comparable Australian municipal and industrial treatment trains are also covered in the Industrial ETP and DAF System for a Factory in Sydney, Australia: 2026 Engineering Guide.
FAQ
What is the headline scope of the Subiaco upgrade?
An initial $105 million for detailed design, engineering and site preparation at the Lemnos Street site, with a planned 23 million litres per day capacity increase, according to The National Tribune. The current 65 million litres per day load comes from 120,000 existing homes and businesses.
How many homes and what population is the upgrade designed to support?
The project is reported to support 60,000 future homes and new homes for more than 135,000 people over a 25-year horizon, per The National Tribune, with redevelopment sites at Subi East, Belmont Park Racecourse and Fremantle Port cited.
What are the likely procurement steps and lead-time signals?
The $105 million is explicitly for detailed design, engineering and site preparation, not full construction, which signals a design-then-build pathway rather than a single turnkey award, as reported by The National Tribune. The supplied sources do not report a construction award date, main works contract value, or supplier shortlist, so a buyer comparing lead times cannot rely on those numbers from this report.
Will the upgrade change effluent quality or reuse capability?
The state government says the project will improve treatment quality, increase opportunities to recycle water and reduce demand on drinking supplies, according to The National Tribune. The supplied sources do not report specific BOD, TSS or reuse-class targets, so those technical numbers are not available from this report.
